How Bad Is It to Have a Drink Before Working Out?

Just to clarify: We're talking adult beverages, not Gatorade. And the answer is, actually, it depends. Here are some scenarios.

1. You hit happy hour but still plan to Spin.

Skip class. Even one drink impairs coordination and balance, says sports dietitian Molly Kimball, R.D. (Do you really want to explain why you fell off a stationary bike?) Plus, research shows bartenders routinely overpour cocktails by about 42 percent, so you may be drinking more than you think. Really, it's not worth it: "Alcohol is a drag on your energy. You move slower, push yourself less and burn fewer calories," Kimball says. Ride the buzz now and the bike when you're sober.

2. It’s 7 a.m. and last night was a real doozy.

Suck it up and go, says Aaron Michelfelder, M.D., professor of family medicine at Loyola University Health System in Chicago. “Exercise increases blood flow to the liver and kidneys, allowing them to flush out alcohol and its hangover-producing by-product, metabolites,” Dr. Michelfelder says. A greasy egg sandwich can’t do that. OK, you won’t be on your A-game. But take a B vitamin (alcohol depletes levels), chug water and sweat out the Cuervo.

3. You’re running a race with boozing built in.

Play it smart. Trendy brew-to-brew runs hand you cold ones during the event, so it’s clear: no PR today. But B-to-Bs are about a beer-cheers blast with friends, not competing. To keep the good times rolling, not an ankle, don’t try to match drinks with dudes. (Women “feel” alcohol faster, says Gig Leadbetter, Ph.D., kinesiologist at Colorado Mesa University, and running while drinking enhances the clumsiness.) Stick to one beer on the course. Afterward? Game on.